The present invention relates to apparatus for the control of vacuum suction used with medical devices in order to aspirate fluids and gases that collect in body cavities of patients. More particularly, the present invention relates to an electronic suction regulator for regulating the vacuum suction generally available in hospitals for use in aspirating fluids and gases that collect in body cavities of patients because of injury, disease or surgery.
The use of vacuum suction regulators as medical devices is well known for aspirating fluids and gases from patients in hospitals. Generally, such vacuum suction regulators attach to a vacuum outlet in the wall of a patient's hospital room. Known vacuum suction regulators include a variable vacuum regulator, a vacuum gauge and a mechanical mechanism which cycles the vacuum on and off at predetermined time intervals. Such known vacuum suction regulators are mechanical devices. They utilize the vacuum source as a means of powering the cycling mechanism. In addition, although such known mechanical vacuum suction regulators are field adjustable, the intervals over which they may cycle the vacuum on and off are set at the factory to, for example, 18 seconds on and 8 seconds off. One such type of known mechanical vacuum suction regulator is that marketed under the name VACUTRON by the assignee of the instant application.
Such known mechanical vacuum suction regulators achieve vacuum cycling by means of precise air flow rates into and out of an air chamber. That chamber includes a rubber diaphragm which allows the volume in the chamber to increase and decrease on a periodic basis. The diaphragm is connected to a mechanism that cycles the vacuum on and off. In order to control the on/off time periods, two needle valves control the air flow into and out of the diaphragm. Problems arise with such known devices due to the fact that the on/off time periods are fairly long and total air chamber volume quite small. Therefore, in order to operate at such small flow rates, the valve openings themselves are also small. The small valve openings make the timing of the vacuum suction regulator sensitive to clogging by means of small dirt particles in the vacuum line.
Other types of known mechanical vacuum suction regulators also utilize vacuum as a means to power the suction regulator, however, they are operated by a pneumatic logic type system. However, such devices also are subject to becoming clogged by means of small dirt particles.
In order to reduce the negative characteristics of the known mechanically-operated vacuum driven vacuum suction regulator systems, their manufacturers have installed micron-type filters within the suction regulators in order to reduce the effect of minute dirt particles. However, the use of such filters is inconvenient since they must be replaced periodically. Another difficulty with the known mechanically operated vacuum driven vacuum suction regulators is that they are subject to being frequently dropped, thereby damaging the sensitive vacuum gauges contained within. Once dropped, it is necessary for such devices to be returned to the factory for an expensive repair.
An additional problem with the known mechanically operated vacuum suction regulators is that a certain amount of noise is generated by their operation which can be annoying to patients.